Many people suffer from posterior tibial tendon dysfunction (PTTD) and other medial or lateral tendon dysfunctions. Prior devices for applying corrective pressure to a foot or ankle affected by tendon dysfunction have used static implants and other structures and have relied largely on a static pressure application to support the limb. An example of such a device is a foot orthoses, featuring a molded or carved material placed under the foot. These devices apply a constant corrective ground reaction force that may only be adjusted by adding or subtracting material beneath the foot. In many cases, these devices are quite painful for the user and do not provide optimal corrective and other support to the user's foot. Improved devices are needed.